Glossary 59
hub
A group of circuits connected at one point on a network.
insertion loss
In an optical fiber system, the total optical power loss caused by insertion of an optical component, such as a connector, splice, or coupler. Usually given in dB.
kbps
thousands of bits per second
A measure of the bandwidth on a data transmission medium. One kbps equals 1000 bps.
lambda
See wavelength.
LAN
local area network
A data communications network that is geographically limited (typically to a 1 km radius), allowing easy interconnection of terminals, microprocessors, and computers within adjacent buildings. Most notable of LAN topologies are Ethernet, token ring, and FDDI.
laser
An acronym for "Light Amplification by Stimulated Emission of Radiation". A laser is a monochromatic (same wavelength), coherent (waves in phase), beam of radiation.
loss
The ratio of optical output power to input power, usually given in units of dB. Usually represents a decrease in an optical signal. A negative loss means a gain of power.
loss/attenuation
In an optical fiber, the absorption of light by molecules in the fiber, causing some of the intensity of light to be lost from the signal. Usually measured in dB.
